【单选题】298K 时氨水的 K b Ɵ =1.8×10 -5 ,溶液中 [OH - ]= 2.40×10 -3 mol·L -1 ,则氨水的浓度 (mol·L -1 ) 是 ( )
【单选题】A small plane crashed into a hillside five miles east of the city, ________ all four people on board.
【单选题】.A small plane crashed into a hillside five miles to the east of the city, _____ all on board.
【单选题】The hospital is _____ five miles from the station. [ ]
【单选题】A small plane crashed into a hillside five miles east of the city, ________ all four people on board.
【多选题】国家对消费者权益保护主要表现在以下( )途径。